Magazine downdraft furnace



May 10, 1949. E. M. FRANKLIN MAGAZINE DOWNDRAFT FURNACE Filed MW. 23, 1945 fg/vssr M. fEAA/KL/N By and amount of air admitted to the housing l1 and to the chamber 23 may be regulated by adjusting the dampers l9 and 26 so that maximum efficiency is had under different conditions. As the fuel is consumed, it moves downwardly along the inclined grate bars so that additional fuel will be supplied from the hopper H by gravity to keep a bed of substantially uniform relatively shallow depth on the grate.

From the foregoing description, it is believed that the construction, operation and advantages of the present invention will be readily understood and appreciated by those skilled in the art. Minor changes may be made in details of construction, such as fairly fall within the scope of the invention as claimed.

I claim:

1. In a stove or furnace construction, a firebox having a grate therein, said grate includin rearwardly and downwardly inclined grate bars consisting of open-ended tubular members having their forward upper ends opening through the front of the fire-box for the admission of outside air thereto, an ash pit below the grate and fire-box, means forming a combustion chamber rearwardly of the ash pit and communicating with the latter below the grate, means forming a down draft chamber rising from the firebox and having an opening in the upper portion of the rear wall thereof, an air fiue at the back of said downdraft chamber communicating at its upper end with the top of said downdraft chamber through said opening, said grate bars opening at their rear lower ends into the bottom of said air flue, said downdraft chamber having an opening in the front wall thereof for the inlet of fuel directly above the grate, and a feed hopper for the fuel communicating at its bottom with said fuel inlet opening and adapted to feed the fuel onto the grate as the fuel is consumed on the latter.

2. In a stove or furnace construction, a firebox having a grate therein, said grate including rearwardly and downwardly inc-lined grate bars consisting of open-ended tubular members having their forward upper ends opening through the front of the fire-box for the admission of outside air thereto, an ash pit below the grate and fire-box, means forming a combustion chamber rearwardly of the ash pit and communicating with the latter below the grate, means forming a down draft chamber rising from the firebox and having an opening in the upper portion of the rear wall thereof, an air flue at the back of said downdraft chamber communicating at its upper end with the top of said downdraft chamber through said opening, said grate bars opening at their rear lower ends into the bottom of said air flue, said downdraft chamber having an opening in the front wall thereof for the inlet of fuel directly above the grate, a feed hopper for the fuel communicating at its bottom with said fuel inlet opening and adapted to feed the fuel onto the grate as the fuel is consumed on the latter, a housing extending across the front of the fire-box and having an air inlet opening in the front thereof, and a damper controlling said air inlet opening, said grate bars commu- 4 nicating at their forward ends with said housing.

3. In a stove or furnace construction, a firebox having a grate therein, said grate including rearwardly and downwardly inclined grate bars consisting of open-ended tubular members having their forward upper ends opening through the front of the fire-box for the admission of outside air thereto, an ash pit below the grate and fire-box, means forming a combustion chamber rearwardly of the ash pit and communicating with the latter below the grate, means forming a down draft chamber rising from the fire-box and having an opening in the upper portion of the rear wall thereof, an air flue at the back of said downdraft chamber communicating at its upper end with the top of said downdraft chamber through said opening, said grate bars opening at their rear lower ends into the bottom of said air flue, said downdraft chamber having an opening in the front wall thereof for the inlet of fuel directly above the grate, a feed hopper for the fuel communicating at its bottom with said fuel inlet opening and adapted to feed the fuel onto the grate as the fuel is consumed on the latter, and means for controlling the admission of air to the forward ends of said grate bars.

4. In a stov or furnace construction, a firebox having a grate therein, said grate including rearwardly and downwardly inclined grate bars consisting of open-ended tubular members having their forward upper ends opening through the front of the fire-box for the admission of outside air thereto, an ash pit below the grate and fire-box, means forming a combustion chamber rearwardly of the ash pit and communicating with the latter below the grate, means forming a down draft chamber rising from the fire-box and having an opening in the upper portion of the rear Wall thereof, an air flue at the back of said downdraft chamber communicating at its uper end with the top of said downdraft chamber through said opening, said grate bars opening at their rear lower ends into the bottom of said air flue, said downdraft chamber having an opening in the front wall thereof for the inlet of fuel directly above the grate, a feed hopper for the fuel communicating at its bottom with said fuel inlet opening and adapted to feed the fuel onto the grate as the fuel is consumed on the latter, means forming a secondary combustion chamber rearwardly of and communicating with the ash pit below the grate, said secondary combustion chamber having a top air inlet opening behind said air flue, and means controlling the admission of outside air to said secondary combustion chamber through said top opening of the latter.

ERNEST M. FRANKLIN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 

